The present invention relates to compact precision rifle which may be broken down for transport, reassembled, and employed to engage a target up to 500 meters away without the need to re-zero rifle before engagement.
A rifle is a collection of components designed to enable an operator to place a round as close as possible to a chosen target located some distance from the operator. Generally, traditional components may be grouped into four categories based on function. In one example, a first group, which will be referred to as the “trajectory group”, comprises those components which are in direct contact with the round from the moment of ignition until the bullet leaves the firearm, and establish the bullet's trajectory. Exemplary primary components of a trajectory group are a barrel and a chamber. The exemplary barrel can be a metal tube with a uniform interior diameter through which the bullet travels after ignition. Affixed to an end of the barrel is the chamber. The exemplary chamber is a metal tube with a larger interior diameter than the barrel, which holds the cartridge ready for firing. The exemplary cartridge, also known as a “round” or “load”, consists of a cartridge case, primer, powder and bullet.
An exemplary second generalized group comprises those components involved in handling live cartridges and empty cartridge cases, and triggering activation of the primer. Some exemplary primary components of the second group include the action, receiver, bolt, firing mechanism, trigger, and magazine. In this example, the term “action” refers to a mechanism which inserts the live cartridge into the chamber and removes the cartridge case after firing. In some examples, action can also refer to a mechanism which positions a firing mechanism to contact the primer. The exemplary bolt can be a component of the exemplary action and can include a firing pin which will strike the primer when triggered, resulting in ignition of powder. The exemplary receiver can be a component of the action which guides the bolt and secures the bolt at the base of the cartridge. In at least some examples, the term “trigger” can refer to a mechanism which releases the firing pin to contact the primer.
An exemplary third group can comprise those components which hold the first and second groups and fit the firearm to the operator. Exemplary primary components of this third group, which will be referred to as the “stock”, can include a buttstock, forend and grip. The exemplary buttstock can be a portion of the firearm shouldered by the operator. The exemplary grip can be a portion held by an operator's hand which will activate the trigger. The exemplary forend can be a portion of the stock closest to the barrel which may be held by the operator's other hand. The exemplary forend can also form a portion of the stock which is stabilized on a fixed object or bipod during employment.
An exemplary fourth group can comprise a sighting system. This group can include any modality utilized by the operator to aim the firearm. In the case of exemplary embodiments of the present invention, the sighting system can include a scope mounted to the outer surface of the chamber.
When it comes to effectively engaging targets at the ranges contemplated in at least some embodiments of this invention, two parameters or designs that influence desired results can include weapons accuracy and precision with which it may be employed. Though “accuracy” and “precision” are often considered synonyms, they are in fact distinct characteristics affecting whether target will be effectively engaged with each functioning of the rifle. In this context, “accuracy” refers to how closely grouped a series of shots will be, while “precision” refers to the ability to repeatedly bring the accuracy to bear on a particular aimpoint. An exemplary embodiment rifle's inherent accuracy may be measured by operating the firearm from a mechanical support structure which removes the influences of the operator on the trajectory of the bullet.
A rifle's inherent accuracy is affected by even very minor deviations in manufacturing, assembly and functioning of the firearm. Deviations of a rifle barrel can be measured, for example, to the ten-thousandth of an inch. Individual component and interface deviations from an exemplary normative perfect can be combined into a “tolerance-stack” model. The tolerance-stack affects trajectory of the bullet and these effects are magnified by the range to a target. In other words, if a distance between any two rounds of a three round group was one inch or less when a target was 100 meters from an operator, then the distance would expand or increase five inches if the target were 500 meters away. Thus, an accurate rifle is one with a smallest desired tolerance-stack. Effects of atmospheric conditions and differences in ammunition are ignored for purposes of at least some embodiments of this invention.
An exemplary rifle's inherent accuracy, as opposed to the precision with which it may be employed, is most affected by deviations within a trajectory group. A trajectory group can be defined as a group with a direct impact on a trajectory of a fired bullet. In an instant following release of a firing pin, all mechanical actions have completed and errors affecting a trajectory of a fired bullet are those originating in a chamber and barrel. In this context, a critical interface impacting accuracy is one between the chamber and the barrel.
The deviations from the normative perfect found within the barrel and the chamber are the result of the manufacturing process. The deviation resulting from the mating of the chamber to the barrel at the critical chamber/barrel interface is created during the rifle's assembly. In order to employ a weapon with precision, an operator will “zero” a rifle. Zeroing a rifle is the process whereby adjustments are made to the sighting system to bring the operator's view of the aimpoint into alignment with an impact point of a three-round group. Generally, an operator can fire three rounds at a desired aimpoint and observe projectile or bullet impacts. The operator then measures a distance of the impacts from the aimpoint and makes adjustments to the sighting system to correct for deviation. These adjustments compensate for a trajectory group's tolerance stack and allow the weapon to be used with increased precision. So long as new errors are not introduced into the tolerance stack, this alignment of the sighting system to the rifle's inherent accuracy will not need to be re-accomplished. However, if errors are introduced, such as by optics being removed or a barrel being separated from a chamber, then the operator will be unable to engage a target with any confidence that a bullet will hit its mark until the weapon is re-zeroed.
A take-down rifle can be defined as a rifle which is designed to be transported in two or more pieces which are each shorter than a fully assembled rifle. Creation of a take-down rifle was most commonly achieved in existing designs by an inclusion of a mechanism whereby a barrel was easily separated at a barrel/chamber interface while a chamber remained affixed to the rest of the firearm. While a barrel/chamber interface and affixed chamber approach does result in a compact weapon, it also disturbs critical barrel/chamber interface, thus ruining the weapon's zero. Alternatively, other approaches merely removed the stock from the rifle while the trajectory group remained intact. This approach preserves the rifle's zero but does not create a truly compact package for transportation. Neither of these approaches are adequate for scenarios calling for transporting the rifle in a disguised manner, assembling the rifle, and engaging a target at 500 meters without the opportunity to reestablish zero.
Various embodiments of this disclosure move the take-down point from within the critical trajectory group and into the second generalized group to a point which will not affect either the rifle's zero or its inherent accuracy. The critical barrel chamber interface remains undisturbed and the sighting system, being mounted to the outer surface of the chamber, will retain its corrections for the error stack. The exemplary primary take-down point is established by dividing the receiver into two pieces at a selected distance from a rear of a chamber. At a point where such a division is created, the receiver is serving only as a guide for travel of a bolt as it locks a live round into the chamber and extracts the spent cartridge case. Thus, creating an interface between a forward portion of the receiver and a rearward portion of the receiver will have no impact on the rifle's inherent accuracy. An exemplary rifle may be even further broken down by creating a second take-down point within its stock wherein a buttstock is separated from a grip. By utilizing this exemplary approach, it will be possible to break down a rifle so that it may be carried within a brief case or other similarly sized container, assembled, and used to engage a target at 500M without a need to reestablish zero.
Additional features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of the illustrative embodiment exemplifying the best mode of carrying out the invention as presently perceived.